The search for potent and effective analgesics continues to be a significant research goal in the medical community. A substantial number of medical disorders and conditions produce pain as part of the disorder or condition. Relief of this pain is a major aspect of ameliorating or treating the overall disorder or condition. Pain and the possible alleviation thereof is also attributable to the individual patient's mental condition and physical condition.
Opioid and non-opioid drugs are the two major classes of analgesics (A. Dray and L. Urban, Ann. Rev. Pharmacol. Toxicol., 36:253-280, (1996)). Opioids, such as morphine, act at opioid receptors in the brain to block transmission of the pain signals in the brain and spinal cord (N. I. Cherney, Drug, 51:713-737, (1996)). Non-opioids such as non-steroid anti-inflammatory agents (NSAIDs) typically, but not exclusively, block the production of prostaglandins to prevent sensitization of nerve endings that facilitate the pain signal to the brain (Dray, et al., Trends in Pharmacol. Sci., 15:190-197, (1994); T. J. Carty and A. Marfat, “COX-2 Inhibitors. Potential for reducing NSAID side-effects in treating inflammatory diseases”, Emerging Drugs: Prospect for Improved Medicines. (W. C. Bowman, J. D. Fitzgerald, and J. B. Taylor, eds.), Ashley Publications Ltd., London, Chap. 19., pp. 391-411).
Certain compounds, with primary therapeutic indications other than analgesia, have been shown to be effective in some types of pain control. These are classified as analgesic adjuvants, and include tricyclic antidepressants (TCAs) and some anticonvulsants such as gabapentin (Williams et al., J. Med. Chem., 42:1481-1500 (1999)). They are used increasingly for treatment of pain, especially for pain resulting from nerve injury due to trauma, radiation, or disease.
(1S,5S)-3-(5,6-Dichloro-3-pyridinyl)-3,6-diazabicyclo[3.2.0]heptane, and its salts, are novel compounds that demonstrate utility in treating pain and disorders associated with the nicotinic acetylcholine receptor (nAChR). (1S,5S)-3-(5,6-Dichloro-3-pyridinyl)-3,6-diazabicyclo[3.2.0]heptane, and salts thereof, may also have utility when administered in combination with an opioid such as morphine, a non-steroid anti-inflammatory agent such as aspirin, a tricyclic antidepressant, or an anticonvulsant such as gabapentin or pregabalin for treating pain and disorders associated with the nicotinic acetylcholine receptor.
WO 01-81347 discloses diazabicyclo[3.2.0]heptanes that are analgesic agents.